The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of certain physiological abnormalities. For example, lactate, fructosamine, cholesterol, bilirubin, alcohol, and drugs may be monitored or tested in certain individuals. The monitored or tested body fluids may include blood, interstitial fluid, saliva, or urine. In particular, determining glucose in body fluids is important to diabetic individuals who must frequently check the glucose level in their body fluids to regulate the glucose intake in their diets.
One method of monitoring or testing body fluids is with a portable, hand-held blood testing device. The portable nature of these devices enables the users to conveniently test their blood wherever the user may be. The testing device includes a biosensor to harvest the fluid sample for analysis. One type of biosensor is the electrochemical biosensor. The electrochemical biosensor includes a reagent designed to react with analytes in the fluid sample to create an oxidation current at electrodes disposed within the electrochemical biosensor which is directly promotional to the user's blood glucose concentration or analyte being detected. Such a biosensor is described in U.S. Pat. Nos. 5,120,420, 5,660,791, 5,759,364, and 5,798,031, each of which is incorporated herein in its entirety. Another type of sensor is an optical biosensor, which incorporates a reagent designed to produce a colorimetric reaction indicative of analytes in a user's blood or fluid sample. The calorimetric reaction is then read by a spectrometer incorporated into the testing device. Such an optical biosensor is described in U.S. Pat. No. 5,194,393, which is incorporated herein by reference in its entirety.
Biosensors in this “strip” form, i.e., test strips that include a reagent area on an elongated body, are generally inexpensive to produce. However, such sensors, and particularly optical sensors, are not conducive to optical testing because the read head of a meter that is required to analyze and read the sample requires protection from contamination by the sample. One solution to this problem is to wrap a sensor around the read-head so as to cover the read-head and prevent the sample from contacting the read-head. However, it is difficult to devise a method to remove such a sensor from a container without requiring intricate manipulations by a user. The average consumer is typically unwilling nor capable of intricate handling of such optical sensors and corresponding meters.
A need therefore exists for further improvements to sensors and methods for manufacturing sensors that require minimal costs and better handling of the sensors, as well as devices, systems, and methods for storing and handling sensors that are inexpensive and easy to use.